Application of microwave engineering, Microwave Transmission lines and Microwave filters

            In microwave engineering high frequency and short wavelength make unique opportunities for the microwave systems. This is because of following consideration:

§  Antenna gain is proportion to the electrical size of the antenna. At higher frequencies, more antenna gain is therefore possible for a given physical antenna size, which has important consequences for implementing miniaturized microwave system.

§  More bandwidth can be realized at higher frequencies.

§  Microwave signals travel by line of sight and are not bent by the ionosphere as are lower frequency signals. Satellite and terrestrial communication links with very high capacities are thus [possible, with frequency reuse at minimally distant locations.

§   The effective area of radar target is usually proportional to target’s electrical size.

§  Various molecular, atomic and nuclear resonances occur at microwave frequencies, creating a variety of unique applications in the areas of basic science, remote sensing, medical diagnostics and treatment, and heating methods.

 Microwave Transmission lines:

Transmission lines that are use to convey microwave frequency signals called microwave transmission lines.

In an electronic system, the delivery of power requires the connection of two wires between the source and the load. At low frequencies, power is considered to be delivered to the load through the wire.

In the microwave frequency region, power is considered to be in electric and magnetic fields that are guided from place to place by some physical structure. Any physical structure that will guide an electromagnetic wave place to place is called a Transmission Line.

     Microwave filters:

Microwave filters represent a class of electronic filter design to operate on signals in the MHz to GHz frequency ranges. This frequency range is the range used by most broadcast radio, television,

wireless communications like Cell phone, Wi-Fi, Wi-Max and the most radio frequency and microwave devices will include some kinds of filtering on the signals transmitted or received. Such filters are commonly used as buildings blocks to duplexers and diplexers to combine or separate multiple frequency bands.

There are mainly four types of filters with respect to functions,

·         Low-pass filter

·         High-pass filter

·         Band-pass filter

Band-stop filter